Governing mechanism for steam-turbines.



0. BANNER.

GOVERNING MECHANISM FOR STEAM TURBINES.

APPLICATION FILED APR. 28, 1914.

1,201,675. Patented 00t.'17,1916.

UNITED STATES PATENT onrron.

OTTO BANNER, OF EASTON, PENNSYLVANIA, ASSIGNOR TO INGERSOLL-RAND COM- PANY, OF JERSEY CITY, NEWJERSEY, A CORPORATION OF NEW JERSEY.

GOVERNING MECHANISM FOR STEAM-TURBINES.

. Specification of Letters Patent.

Patented oct. 17, 1916.

Application filed April 28, 1914; Serial No. 834,890.

- adapted to be used through a considerable range of loads.

The object of this invention is to provide a turbine which can be operated at a high average efliciency through a wide range of loads, such a machine being adapted for instance, for use with dynamos or blowing engines driven by a turbine which may at one time be required to run at half normal load or less and at'other times at twice or more than twice its normal load. This object and others further to be described are accomplished by the turbine, a practical embodiment of which is shown in the accompanying drawing, in which,

Figure 1 shows a longitudinal section of the turbine, the lower part being in elevation, Fig. 2 shows a plan' of the turbine partly in section on the line 22 of Fig. 1. In the drawings the turbine is shown as comprising a horizontally split casing 1,

divided by dia'phragms or partitions 2, 3,

4, 5 into a high pressure chamber 6, low pressure chambers 7, 8 and 9 and an exhaust chamber 10 which preferably leads by an exhaust conduit 11 to a condenser, (not shown). In the high pressure chamber 6 rotates a high pressure wheel 12 to the blades of which fluid is supplied by a SQI'IQSI of nozzles 13, 14, 15 and 16 which lead, respectively, from steam chests 17, 18, 19 and Steam is serially admitted to these steam chests from a high pressure steam conduit 21 by means of valves 22 which are successively opened as the load increases by means of any suitable regulating mechan sm, such as shown, for instance, in my previous Patent No; 1,117,306 granted November 17th,

1914, which consists of pistons 23 attached to the valves 22, these pistons being raised .and lowered by fluid pressure under the influence of pilot valves 24, these pilot valves 24 being, in turn, ralsed and lowered by arms 25 on the rock shaft 26 operated from the governor of the turbine.

Under normal operating conditions all the steam from the exhaust of the high pressure wheel 12 will pass in series through low pressure stage wheels 27, 28, 29 and 30 to the exhaust chamber 10 and thence to the condenser. 'In such a case high pressure steam would only be passing through nozzles steam cannot pass with suflicient rapidity through the low pressure stages. This will cause the pressure .to rise throughout the whole turbine, materially affecting its efliciency.

To take care. of the excess steam in the high pressure chamber 6 under overload conditions a low pressure wheel 31 is provided in the exhaust chamber 10 of the turbine.

Under .normal conditions the blades of this wheel receive no steam and simply revolve in the low pressure of the exhaust chamber. Under overload cdnditions fluidissupplied to the wheel 31 by groups of nozzles 32 and 33 supplied by conduits 34 and 35 to which steam is admitted from the high pressure chamber 6 by means of valves 36 and '37. Valves 36 and 37 are controlled by pistons 38 similar in construction to piston 23, these pistons being raised and lowered by pilot valves 39 attached to levers 40 which are in turn attached to a rock shaft 41. The rockshaft 41 is connected to rock shaft 26 by arms 42 and 43 and 1ink44, motion of rock shaft'26 causing a similar motion of rock shaft 41. The opening of the various valves controlling the admission of steam to high pressure wheel 12 and low pressure wheel 31 are so arranged by means, for instance, such as shown in my co-pending application, that under increasing load conditions steam will the additional steam which can be efliciently admitted tothe high pressure wheel 12 by opening more nozzles, can be carried off and expanded efiiciently in the low pressure wheel 31 thus permitting the low'pressure Wheels 27 to 30 to receive only a normal amount of steam. As the Wheel 31 under normal load conditions is rotated in a vacuum or in low pressure steam, its movement absorbs very little energy when it is not in active operation.

Although the wheel 12 and the wheels 27 to 30 are shown as provided each with a single row of blades, any suitable number of rows of blades and any suitable number of high and low pressure .wheels may be provided, the low pressure wheels being of the reaction type, if desired. Likewise, although the low pressure wheel 31 is shown with two rows of blades any suitable number of blades or any number of wheels may be provided. Likewise, any suitable governing mechanism and number of nozzles or nozzle groups may be provided for the high pressure wheel 12 and the low pressure wheel 31, and, if desirable, the admission to the low pressure wheel 31 may be governed by the pressure in the chamber 6 instead of directly by the load.

It is to be understood that the present showing and description discloses only one specified modification of the invention, and

other forms and modifications are included in the spirit and scope ofthe invention as expressed in the claims.

I claim- 1. In a fluid operated turbine, a high pressure stage, two low pressure stages, one of said low pressure stages being normally inactive, means -for continuously supplying fluid from the discharge of said high pressure stage to one of said low pressure stages, and meansfor supplying fluid from the discharge of said high pressure stage to said normally inactive low pressure stage only under greater load conditions.

2. In a fluid operated turbine, a high pressure wheel, a series of: low pressure wheels continuously receiving steam from said high pressure wheel, a normally inactive low pressure wheel located in the exhaust of said continuously supplied low pressure wheels, and means for supplying steam from the discharge of said high pressure wheel to said normally inactive low pressure wheel under greater load conditions.

3. In combination with a steam turbine comprising a high pressure stage and a series of low pressure stages adapted to receive steam continuously from the discharge of said high pressure stage, a normally inactive low pressure stage, and means governed by the load to supply a greater amount of live steam to said high pressure stage, and to supply fluid from the discharge of said high pressure stages to said normally inactive low pressure stages under overload conditions.

4. In a fluid operated turbine, a casing having a high pressure chamber, a series of low pressure chambers, and an exhaust chamber, a high pressure wheel in said high pressure chamber, means for supplying steam to said high pressure wheel, low pressure wheels in said low pressure chambers, said low pressure wheels continuously receiving steam from the discharge of said high pressure wheel and discharging said steam into said exhaust chamber, a normally inactive wheel in said exhaust chamber, and means for conveying fluid to said normally inactive wheel from the discharge of said high pressure wheel under greater load'conditions.

5. In a fluid operated turbine, a high pressure wheel, a series of low pressure wheels having single rows of blades, nozzles for admitting fluid to said high pressure wheel nozzles for admitting fluid from the discharge of said high pressure wheel continuously to said low pressure wheels, a normally inactive low pressure wheel having a plu rality of rows of blades, and means for ad mitting fluid from the discharge of the high pressure wheel to said normally inactive wheel under greater load conditions.

6. In a steam turbine, a high pressure wheel, a series of valves for admitting fluid to said high pressure wheel, a low pressure wheel, means for continuously admitting fluid from the dischargeof said high pressure wheel to said low pressure wheel, a second low pressure wheel, a conduit leading from the discharge of said high pressure wheel to said second low pressure wheel, a valve controlling said conduit/and load governed means for successively opening said high pressure valves and for opening said conduit controlling valve with a late opening high pressure valve.

7. In a steam turbine, a casing, a series of turbine wheels therein, means to pass fluid through said wheels in series, an exhaust chamber receiving the discharge from said wheels, a normally inactive wheel in said exhaust chamber and means to supply fluid from an earlier'normally active wheel to said inactive wheel under greater load conditions.

In testimony whereof, I have hereunto set my hand.

OTTO BANNER.

\Vitnesses I PAUL HOFFMAN, F. A. POPE. 

